CN108474534B

CN108474534B - Lighting unit for a motor vehicle headlight for generating a light beam with a light-dark boundary

Info

Publication number: CN108474534B
Application number: CN201780006801.0A
Authority: CN
Inventors: B.艾钦格
Original assignee: ZKW Group GmbH
Current assignee: ZKW Group GmbH
Priority date: 2016-01-14
Filing date: 2017-01-09
Publication date: 2021-11-23
Anticipated expiration: 2037-01-09
Also published as: EP3403021B1; AT518109A1; KR20180103962A; KR102145335B1; CN108474534A; WO2017120630A1; AT518109B1; EP3403021A1

Abstract

The invention relates to a lighting unit for a motor vehicle headlight for generating a light beam having a light-dark boundary, comprising: -at least one light source (1, 1a, 1 b), -a mirror (2), -an exit lens (3) having an outer surface (3 a), -a focal line region (4) which is arranged between the mirror (2) and the exit lens (3), and further having a collimator (10, 10a, 10 b) for each light source (1, 1a, 1 b), respectively, wherein the collimator (10, 10a, 10 b) orients a light ray (S1) fed into the collimator (10, 10a, 10 b) by the light source (1, 1a, 1 b) assigned to it into a light beam of light rays (S2), and wherein the mirror diverts the light rays of the light beam exiting from the collimator into a focal line in the focal line region, and wherein the light rays exiting from the mirror are diverted by the exit lens at least in the vertical direction, in such a way that the light rays exiting from the exit lens form a light distribution with a light-dark boundary, and wherein the outer surface (3 a) of the exit lens (3) is formed by a groove-shaped structure in the smooth base surface (BF), wherein the grooves (3 b) forming the groove-shaped structure run in a substantially vertical direction, and wherein preferably two grooves (3 b) each arranged next to one another in the horizontal direction are separated by a projection, in particular a substantially vertically running projection, which preferably extends over the entire vertical extension of the grooves (3 b).

Description

Lighting unit for a motor vehicle headlight for generating a light beam with a light-dark boundary

Technical Field

The invention relates to a lighting unit for a motor vehicle headlight for generating a light beam with a light-dark boundary, comprising:

-at least one light source,

-a mirror for reflecting the light emitted by the light source,

-an exit lens having an outer surface,

a focal line region arranged between the mirror and the exit lens,

and also a collimator for each light source, wherein the collimator orients the light fed into the collimator by the light source assigned to it into a light beam of light rays,

and wherein the mirror diverts light rays of the light beam emerging from the collimator into a focal line in the region of the focal line,

and wherein the light reflected by the mirror is deflected by the exit lens at least in the vertical direction in such a way that the light emerging from the exit lens forms a light distribution with a light-dark boundary, wherein the light-dark boundary is obtained as a focal line or an image of a focal line region by the exit lens,

and wherein the one or more of the one or more,

the mirror, the exit lens and the focal line region, and preferably the at least one collimator, are formed by a light-transmissive body, and wherein at the mirror interface of the mirror and/or at the interface of the focal line region, and preferably at the collimator interface of the at least one collimator, the light rays propagating in the light-transmissive body are completely reflected.

The invention also relates to a motor vehicle headlight having at least one such lighting unit.

Background

A similar lighting unit is disclosed for example from DE 602006000180T 2.

The lighting unit in combination with the invention can be used in motor vehicle headlamps, for example for realizing a low beam distribution, in particular a portion of the front region light distribution of the low beam distribution.

Current design trends often require headlamps with narrow slit-shaped light exit openings in the vertical direction and with expanded slit-shaped light exit openings in the horizontal direction. The illumination unit mentioned at the outset can be realized in the region of the light exit area with a small overall height, which in some embodiments can be only up to 10mm or up to 15mm high, so that a slit-shaped light exit area extending in the horizontal direction results.

In the case of the lighting unit mentioned at the outset, as is also described in the above-mentioned DE 602006000180T 2, it is provided that the light exit surface, i.e. the outer surface of the exit lens, is smooth. It has been found here that the light pattern or the light distribution achievable in the horizontal direction is often not wide enough.

Disclosure of Invention

The object of the invention is to provide an improved lighting unit.

This object is achieved with the initially mentioned lighting unit in that the outer surface of the exit lens according to the invention is formed by a groove-shaped structure in the smooth base surface, wherein the grooves forming the groove-shaped structure run in a substantially vertical direction, and wherein preferably two grooves each arranged next to one another in the horizontal direction are separated by a projection, in particular a substantially vertically running projection, which preferably extends over the entire vertical extent of the groove. The smooth base surface is preferably C0 continuous and in particular does not have horizontally running edges.

As mentioned at the outset, the width necessary for a desired light pattern, in particular the front-region light distribution for a low-beam light distribution, is often not achievable with a smooth outer surface of the exit lens. The horizontal blurring of the emerging light is achieved by the structure (Struktur) according to the invention on the outer surface of the exit lens, whereby the desired width of the light distribution can be achieved.

Preferably exactly one light source is provided with exactly one collimator.

Preferably, the first base cutting curve obtained when cutting the smooth base surface with the first non-vertical cutting plane can run straight and the first outer surface cutting curve obtained when cutting the outer surface with the first cutting plane has a sinusoidal course.

In particular, provision may be made for the first outer surface cutting curve to have a base cutting curve and sin in the first cutting plane with respect to the respective first cutting plane^N(k x) proportionally, wherein N =1, 2, 3.. wherein x denotes the coordinates along the respective base cutting curve and k denotes a constant.

In this case, it can be provided that the zero crossings of the sinusoidal first outer surface cutting curve lie on the first base cutting curve.

Therefore, the run and sin apply^N(k x) + c, where c = 0.

In particular, it can be provided that the values for the constant k are identical for all first outer surface cutting curves.

It can also be expedient if the second base cutting curve, which is obtained when the smooth base surface is cut with a second vertical cutting plane, which runs parallel to the optical axis of the exit lens, is configured to be curved, in particular curved outward, wherein the second base cutting curve is preferably continuous.

In this connection, it may be expedient for the points of the outer surface to be connected to one another at a maximum distance from the base surface by a second outer surface cutting curve which is obtained when the outer surface is cut with a defined second cutting plane.

In particular, it is advantageous here if, during the progression along the second base cutting curve in the defined cutting plane, the standard distance from the second outer surface cutting curve is a function a(s) of a parameter s which specifies the position on the second base cutting curve.

The second cutting plane is a vertical plane parallel to the optical axis of the light-transmitting body, i.e. of the exit lens of the optical body.

In terms of the optical axis, the optical axis of the optical body defines, in particular, the center line of the optical body with respect to the Apex (Apex) of the exit lens.

The first cutting plane is obtained in the points observed on the base surface as follows: the first cutting plane in the observed point is a plane perpendicular to the tangential plane at the base surface, wherein this plane, i.e. the first cutting plane, is still perpendicular to the second cutting plane in which the point lies. The second cutting plane is, as already mentioned above, a vertical cutting plane through the smooth base surface, which extends parallel to the optical axis (or through the optical axis) and in which the point of observation is located.

In the case of a base surface that is curved only in the vertical direction but extends straight in the horizontal direction perpendicular to the optical axis, although the angle with respect to the optical axis varies between adjacent first cut planes, all the cut planes are straight and extend "parallel" to each other in the horizontal direction perpendicular to the optical axis.

In this case, it is advantageously provided that the standard spacing a(s) continuously increases as one progresses along the second basic cutting curve, wherein preferably the standard spacing at the lower edge of the basic surface is smaller than the standard spacing at the upper edge of the basic surface, wherein the standard spacing a(s) is, for example, in accordance with the relationship a(s) = a₀(K-s) wherein s [0,1 ]]Wherein s =0 denotes a position at the upper edge and s =1 denotes a position at the lower edge, and K =1 or K>1。

For K =1, whereby a₀Is the standard spacing at the upper or lower edge of the base surface (BF), preferably at the upper edge (s = 0), where (s = 1) a (1) =0, respectively.

For the value K>1 applies that the standard spacing a (0) = K a at the upper edge (s = 0)₀And at the lower edge the standard pitch a (1) = a₀* (K–1)>0。

In the case where K >1, better optical efficiency is sometimes shown than in the case where K = 1.

In this design, therefore, there is a second vertical cutting plane in which the "zero crossings" which are respectively superimposed on one another, i.e. the regions in which the outer surface and the base surface coincide, are connected to one another by a respective second outer surface cutting curve which in this case coincides with the second base cutting curve.

Likewise, there is a second cutting plane in which the second outer surface cutting curve interconnects the negative nominal spacing/amplitude. For clarity of description, however, it is sufficient to describe the second outer surface cross-sectional profile for a "positive" standard pitch/amplitude, and the other relationships are derived by a sinusoidal curve in the first cutting plane.

It is possible that the at least one light source is arranged deeper than the focal line region and that the light emitted by the at least one light source is directed upwards for being able to be reflected by the reflector downwards in the direction of the focal line region.

It can also be provided that the at least one light source is arranged higher than the focal line region and that the light emitted by the at least one light source is conducted downwards for being able to be reflected by the reflector upwards in the direction of the focal line region.

Provision is preferably made for the mirror to be a surface, for example a cylinder surface, which has a parabola as a line of conduction, wherein the focal line of the mirror is formed, for example, by a straight line which is preferably substantially parallel to a generatrix of the cylinder. Preferably the parabolic axis is orthogonal to the generatrix and parallel or anti-parallel to the main radiation direction of the at least one light source.

It can also be provided that the mirror is a parabolic surface with a major axis in the vertical direction, which is, for example, cylindrically truncated (beschneiden). But the cut-down need not be cylindrical.

For example, it can be provided that the outer surface of the exit lens is curved outward in the vertical direction and preferably runs straight in the horizontal direction and is formed, for example, by a cylinder surface with a straight cross section along an outwardly convex curve. An example for such an outwardly convex curve is a lens profile called an aspheric surface (asph ä rische).

For example, to free-form lenses that curve outward in the vertical direction and do not curve in the horizontal direction.

In particular, it can also be provided that the cylindrical surface of the outer surface has generatrices which are substantially parallel to the generatrices of the mirror.

Provision may be made for a light source, but provision may also be made for a plurality of light sources to be arranged side by side, for example in the direction of a generatrix of the reflector. Preferably the spacing between the light source emission points or light source emission faces, in particular their light emission centers of gravity, is the same.

The at least one light source includes a light emitting diode or a plurality of light emitting diodes.

In general, in one embodiment of the invention, a sinusoidal groove optic is provided in which the sinusoidal function is perpendicular to the lens surface, i.e., the smooth base surface of the exit lens. The period preferably remains constant, while the groove depth (amplitude) is preferably determined, in particular linearly, for example as described above, from a defined starting value a at the upper edge of the light exit face₀Or A₀K (by which the width of the light distribution can be adjusted) changes to zero or a at the lower edge of the lens₀Value of (K-1).

It is thereby possible to widen the light distribution as desired, and in an unexpected manner, to derive here that the light-dark boundary is not bent outward, even in the case of a straight focal line of the light-transmitting body.

Drawings

The invention is explained in more detail below with reference to the drawings. Wherein the content of the first and second substances,

figure 1 shows the main components of a lighting unit for motor vehicle headlamps according to the invention,

figure 2 shows a vertical section parallel to the optical axis of the lighting unit of figure 1,

figure 3 shows a vertical section parallel to the optical axis of another lighting unit according to the invention,

fig. 4 shows a perspective view of a lighting unit with a light-transmitting body, the exit lens of which has no groove structure,

figure 4a shows a light distribution produced with the lighting unit of figure 4,

fig. 5 again shows the lighting unit of fig. 1 and

figure 5a shows the light distribution produced therewith,

figure 6 shows in vertical section an enlarged cut of the light-transmitting body between its focal line and the light exit face (lichtaurittsfl ä che),

figure 7 shows the course of the light exit face of the exit lens (austritsilise) of the light-transmitting body in a section along the exemplary first cutting plane SE1 of figure 6,

fig. 8 again shows the vertical section of fig. 6, with exemplary sections a-A, B-B, C-C and D-D,

fig. 9a to 9D show the course of the light exit surface of the exit lens of the light-transmitting body for K =1 in different sections a-A, B-B, C-C and D-D according to fig. 8, and

fig. 10a to 10D show the course of the light exit surface of the exit lens of the light-transmitting body for K >1 in different sections a-A, B-B, C-C and D-D according to fig. 8.

Detailed Description

The terms "upper", "lower", "horizontal", "vertical" in the framework of the present description are to be understood as meaning an orientation of the unit if the unit is arranged in a normal position of use after it has been installed in a lighting device installed in a vehicle.

Fig. 1 shows a lighting unit 100 according to the invention for a motor vehicle headlight for generating a light beam with a bright-dark boundary (lichtbund). The lighting unit typically comprises one or more light sources, in the specific example three light sources 1, 1a, 1b, a reflector 2, an exit lens 3 having an outer surface 3a, a focal line region 4 arranged between the reflector 2 and the exit lens 3, and further a

collimator

10, 10a, 10b for each light source 1, 1a, 1b, respectively.

The light sources 1, 1a, 1b preferably each comprise a light emitting diode or a plurality of light emitting diodes.

The mirror 2 diverts (enables) the light rays S2 of the light beam emerging from the

collimator

10, 10a, 10b (austereden) into the focal line FL in the focal line region 4, and the light rays S3 reflected completely by the mirror 2 are diverted by the exit lens 3 of the translucent body 101 at least in the vertical direction V in such a way that the light rays S4 emerging from the exit lens 3 form a light distribution with a bright-dark boundary. The bright-dark boundary is obtained as an image of a focal line region 4 in which the focal line FL is located, by the exit lens 3.

The mirror 2, the exit lens 3 and the focal line region 4 and the

collimators

10, 10a, 10b are formed by an integral translucent body 101, and the light rays S1, S2, S3 propagating in the translucent body 101 are totally reflected at the interface of the mirror 2 and the focal line region 4 and at the collimator interface of the

collimators

10, 10a, 10 b.

The corresponding course of the light is shown in fig. 2 and 3.

The light-transmitting material, the light-transmitting body 101 being formed from a light-transmitting material, preferably has a refractive index (Brechungsindex) greater than that of a body formed from air. The material comprises, for example, PMMA (polymethyl methacrylate) or PC (polycarbonate) and is particularly preferably formed therefrom.

It can be provided that the

collimator

10, 10a, 10b orients the light ray S1 fed into the

collimator

10, 10a, 10b by the light source 1, 1a, 1b assigned to it into a beam of substantially parallel light rays S2, which light beam S2 propagates substantially perpendicularly (normal) to the exit plane E of the

collimator

10, 10a, 10b (ausbreitet).

In contrast, in general and even in particular embodiments, it may be advantageous for the

collimators

10, 10a, 10b to emit light in parallel in a direction (for example along a vertical direction V in the light image) and to fan out accordingly in a direction perpendicular to this direction (horizontal line H in the light image) (auff ä chern). Preferably, the

outer collimators

10, 10b, in particular the two outer collimators, have an asymmetrical emission characteristic in order to avoid reflections and thus inhomogeneities at the side faces of the light-transmitting body 101 (Inhomogenit ä ten).

In this case an embodiment with three light sources and three collimators is shown. However, the use of only a single light source, in particular a light-emitting diode, and a single associated collimator is sufficient to achieve the desired (gewnschte) light distribution.

Thus, the light in front of the focal plane (Fokalebene) exiting the lens is already horizontally scattered (getrieut). By means of the light expansion (Aufweitung), a broad light distribution, in particular a broad front-area light distribution (Vorfeld-Lichtverteilung), can be achieved in cooperation with the scattering optics according to the invention at the front of the light-transmitting body 101, which are also described below.

It is also conceivable to produce an asymmetrical front-area light distribution by adapting the horizontal emission characteristic (abstrahlcharaktertik) in such a way that, for example, a central collimator is asymmetrically implemented. By means of the horizontal grading in the focal line region, an asymmetrical course of the bright-dark boundary can also be used.

The reflector 2 is configured, for example, as a cylinder surface with a parabola as a line of wire, wherein the focal line BL of the reflector is formed by a straight line which is substantially parallel to a generatrix of the cylinder.

The focal line of the mirror FL is in the focal line region 4 of the light-transmissive body 101 and preferably substantially coincides with the focal line of the exit lens 3.

The focal line region 4 is an edge in the light-transmissive body 101. The HD line is formed by imaging the edge 4, which is a curved line, in particular with a small curvature (Kr humung) or particularly preferably a straight line.

Light which emerges as far as possible below the edge 4 through the surface 4a is blocked (abgeschattt) in that the surface 4a lying below the edge 4 is blocked, for example by a light barrier (blend) or a dark, for example black or brown, coating or the like on its outer side, in order to avoid false (Fehl)/scattered light.

The outer surface 3a of the exit lens 3 of the light-transmitting body 101 is curved outward in the vertical direction, to be precise preferably such that in the middle region the exit surface is located further forward in the light exit direction than in the upper and lower edge regions thereof. The exit lens preferably extends straight in the horizontal direction and is formed, for example, by a cylindrical surface having a straight cross section along an outwardly convex curve, or by a free-form lens that is curved outwardly in the vertical direction and is not curved in the horizontal direction.

In particular, it can also be provided that the cylindrical surface of the outer surface 3a has generatrices (erzeugend) which are substantially parallel to the generatrices of the mirror, or preferably the straight sections of the free-form lens are parallel to the generatrices of the mirror 2.

Fig. 2 corresponds to a vertical section through the lighting unit of fig. 1. The light source 1 is here arranged deeper than the focal line region 4 and the light emitted by the light source (ausgehend) is directed upwards for being able to be reflected by the mirror 2 downwards in the direction of the focal line region 4 as has been described in depth.

Fig. 3 shows a substantially similarly constructed lighting unit, with the difference that here the at least one light source 1 is arranged higher than the focal line region 4 and that the light emitted by the at least one light source 1 is conducted downwards for reflection by the reflector 2 upwards in the direction of the focal line region 4.

Fig. 4 shows a lighting unit from which a lighting unit 101' according to the invention is "produced" as has been briefly described in principle in fig. 1 to 3. The lighting unit 101' of fig. 4 has a construction which has been substantially described above, so that a further discussion (Er ribbon) is omitted here. The lighting unit 101 ' shown in fig. 4 has an exit lens 3 ' with a smooth exit face (Austrittsfl ä che) 3a '.

Fig. 4a shows a light distribution with a bright-dark boundary, such as a low beam distribution (abbblindlichverteileung) or a portion, such as the front region of a low beam distribution. This light distribution has a certain width, as is schematically shown in fig. 4 a.

Starting from such a lighting unit 101', the lighting unit 100 already shown in fig. 1 is now shown again in fig. 5.

In contrast to the embodiment according to fig. 4, in the illumination unit 100 of fig. 5 the outer surface 3a of the exit lens 3 is formed by a smooth base surface BF (corresponding to the exit surface 3 a' of fig. 4) which is provided with a trench-shaped structure, wherein the trenches 3b forming the trench-shaped structure run in the vertical direction, i.e. from top to bottom. In particular, the outer surface 3a of the exit lens 3 is formed by a groove-shaped structure in the smooth base surface BF, wherein the grooves 3b forming the groove-shaped structure run in a substantially vertical direction, and wherein preferably two respective grooves 3b arranged side by side in the horizontal direction are separated by a, in particular, substantially vertically running projection (Erhebung), which preferably extends over the entire vertical extension of the grooves 3 b.

As mentioned at the outset, the (notweighed) width necessary for the desired light pattern, in particular the front-area light distribution for the low-beam light distribution, is often not achievable with the smooth outer surface BF, 3 a' of the exit lens. A horizontal blurring (Verwischen) of the emerging light is achieved by the inventive structure on the outer surface of the exit lens, as a result of which the desired width of the light distribution can be achieved, as is schematically shown in fig. 5 a.

Fig. 6-8, 9a-9d, 10a-10d below again show a preferred design of the trench structure according to the invention.

Fig. 6 and 8 show vertical sections through the translucent body 101, to be precise enlarged sections of the translucent body between its focal line FL and the light exit face 3a, respectively.

Fig. 6 shows a vertical second section here, which contains the point P viewed on the base surface BF, and fig. 8 shows a vertical second section SE2, in which four exemplary points PA, PB, PC and PD are situated.

If the smooth base surface BF is cut with a non-vertical first cutting plane SE1 (which cutting plane SE1 is also discussed in more detail further below), for example at point P (fig. 6) or according to the section a-A, B-B, C-C, D-D (fig. 8), a first base cutting curve BSK1 results, which runs straight, wherein the first outer surface cutting curve SK1 (which corresponds to the course of the lens outer surface in the cutting plane SE 1) which results when the outer surface 3a is cut with the first cutting plane SE1 has a sinusoidal course.

A smooth base surface is a hypothetical idea (Konstrukt) with respect to which the outer surface is depicted which is then actually realized. The non-vertical first cutting plane SE1 is a plurality of such non-vertical cutting planes, which are also to be defined exactly below.

In the preferred example shown, the first outer surface cutting curve SK1 relates in the first cutting plane SE1 to the base cutting curves BSK1 and sin of the respective first cutting plane SE1^N(k x) proportionally, where N =1, 2, 3. (N =1 in the example shown), where x denotes the coordinate along the corresponding base cutting curve BSK1 and k denotes a constant.

In this case, it can be provided that the zero crossings of the sinusoidal first outer surface cutting curve SK1 lie on the first base cutting curve BSK 1. Thus, the trends (Verlauf) and sin apply^N(k x) + c, where c = 0.

Fig. 7 shows such an exemplary first cutting plane SE1, with point P in the first cutting plane, which is perpendicular to a tangential plane TE (fig. 6) in which point P lies, to generally illustrate the correlation. In which the outer lens surface is shown with respect to a first base cut curve BSK 1. The base cut curve BSK1 is a straight line with parameter x along the straight line BSK 1. The lens outer contour is in the cross section a first outer surface cut curve SK1, which in this example is proportional to sin (k x). According to the position s corresponding to the point P (see further discussion below regarding the parameter s), that is to say s = s in the section according to fig. 6_pThrough A(s)_p) The maximum Amplitude (Amplitude) is determined as shown in fig. 7. The determination of the amplitude is also discussed in more detail further below.

Fig. 8 shows a cross section along a vertical second cutting plane SE2 parallel to the optical axis Z, with four exemplary observation points PA, PB, PC and PD.

The first cutting plane SE1 is shown in the four points, and the corresponding course of the second outer surface cutting curve SK2 for the four selected cutting planes SE1 (from the sections a-A, B-B, C-C and D-D) is shown in fig. 9 a-9D. For a better overview, the doubled amplitude, i.e. the distance between the maximum and minimum deflection (Auslenkung), is shown in each of these sections.

It can also be seen that, in accordance with fig. 6, the sinusoidal course of the second outer surface cutting curve SK2 is used here for k

Where the period length T. Preferably, it is provided that the value for the constant k is the same for all first outer surface cutting curves SE 1.

Regardless of the embodiment shown, typical values for the period length T mm are in the range up to 2.50mm, preferably up to 2.00 mm. Particularly preferred values are between 0.25mm and 2.50mm, for example between 1.25mm and 2.00 mm.

Regardless of the embodiment shown, for the maximum amplitude a₀[µm]The preferred value of (a) is in the range of 50 to 350 [ mu ] m, and the typical value is 250 [ mu ] m.

As to A₀A suitable value range for the ratio to T gives, for example, 0.1<(T/A₀)<0.250。

The above description applies to the case of K =1 (see further above for the embodiment at the beginning of the description for parameter K), for K>1, where A was in the two preceding paragraphs, similar considerations apply₀Can pass through A₀K substitutions.

Fig. 8 also shows (as also fig. 6), that a second base cutting curve BSK2, which results when the smooth base surface BF is cut with a vertical second cutting plane SE2 running parallel to the optical axis Z of the exit lens 3, is curved, in particular curved outward, wherein the second base cutting curve BSK2 is preferably continuous (stiig).

In this connection, it is provided that a second outer surface cutting curve SK2, which is obtained when the outer surface 3a is cut with a defined second cutting plane SE2, connects points of the outer surface 3a to one another at a maximum distance from the base surface BF. The second plane SE is therefore preferably a vertical cutting plane parallel to the optical axis Z, for which the quantity (betrg) sin is suitable^N(k*x) = 1。The second plane is sufficient for defining the outer surface of the lens, the area between the vertical planes being defined by the sinusoidal function described above.

The standard spacing of the second outer surface cutting curve SK2 from the second base cutting curve BSK2, progressing along the second base cutting curve BSK2 in the defined cutting plane SE2, can be shown as a function a(s) of the parameter s, which describes the position on the second base cutting curve BSK 2.

Returning once again to the first cutting plane, it is said that the first cutting plane SE1 is found in the points P (fig. 6), PA, PB, PC, PD (fig. 8) observed on the base surface BF as follows: the first cutting plane SE1 in the observed point P, PA,.. is perpendicular to the tangential plane TE on the base surface BF, wherein this plane (= cutting plane SE 1) is still perpendicular to the second cutting plane SE2 in which the point P lies. As already mentioned above, the second cutting plane is a vertical cutting plane through the smooth base surface BF, which extends parallel to the optical axis Z (or through the optical axis Z) and in which the point of observation P lies. The first cutting plane SE1 encloses an angle of 90 ° with the second base cutting curve BSK 2.

In the case of a base surface which is curved only in the vertical direction but which runs straight in the horizontal direction perpendicular to the optical axis Z, although the angle with respect to the optical axis Z varies between adjacent first cutting planes SE1, all cutting planes are straight and run "parallel" to one another in the horizontal direction perpendicular to the optical axis Z.

Returning now again to the vertical second cutting plane SE2 and the direction of travel of the outer surface cutting curve SK2, the function a(s) follows, for example, the relation a(s) = a₀(1-s), wherein s [0,1 ]]Wherein A is₀Is the standard spacing at the upper edge of the base surface BF.

S =0 is the position at the upper edge of the base surface, where therefore a (0) = a applies₀At the lower edge, a (1) =0 applies. Thus, the parameter represents the normalized arc length along the cutting curve BSK 2.

For parameter s, the following applies in the four points according to fig. 8:

and the number of the first and second groups,

A(s_PA) = A₀ * 0 = 0, A(s_PD) = A₀ * 1 = A₀and 0< A(s_PB) < A(s_PC) < A(s_PD) = A₀。

Likewise, there is a second cutting plane in which the second outer surface cutting curve connects the negative standard distances/amplitudes to one another. For the sake of clarity, however, it is sufficient to describe the second outer surface cross-sectional curve for a "positive" standard pitch/amplitude, the other relationships being derived by a sinusoidal curve (Verlauf) in the first cutting plane.

The above-described relationship a(s) = a₀(1-s) is the general case A(s) = A₀Special case of (K-s), with K = 1. It has been proven that in some cases K is addressed>1 is better than for K = 1. Typical values for the parameter K are in the range of 1.2-1.45, preferably about 1.33.

In the situation shown in fig. 10a-10d applies

A(s_PA) = A₀ * (K - 1) > 0, A(s_PD) = A₀K, and A₀ * (K - 1) < A(s_PB) < A(s_PC) < A(s_PD) = A₀ * K。

The contour of the outer surface 3a on the "imaginary" base surface BF in general can be expressed as

z(s, x) = A(s) * sin^N(k*x)。

In general, in one embodiment of the invention, a sinusoidal groove optic is provided in which the sinusoidal function is perpendicular to the lens surface, i.e., the smooth base surface of the exit lens. The period preferably remains constant, while the groove depth (amplitude), in particular linearly, is preferably determined from a defined starting value a at the upper edge of the light exit surface₀With which the width of the light distribution can be adjusted, to a value of zero at the lower edge of the lens.

It is thereby possible to achieve that the light distribution is broadened as desired (verbreitert), and it is also possible to obtain in an unexpected manner that the light-dark boundary is not bent outward, even in the case of a straight focal line of the light-transmitting body.

Claims

1. A lighting unit for a motor vehicle headlight for generating a light beam with a light-dark boundary, having:

at least one light source (1, 1a, 1 b),

-a mirror (2),

-an exit lens (3) having an outer surface (3 a),

a focal line region (4) arranged between the mirror (2) and the exit lens (3),

and also a collimator (10, 10a, 10 b) for each light source (1, 1a, 1 b), wherein the collimator (10, 10a, 10 b) orients a light ray (S1) fed into the collimator (10, 10a, 10 b) by the light source (1, 1a, 1 b) assigned to it into a light beam of light rays (S2),

and wherein the mirror (2) diverts light rays (S2) of the light beam emerging from the collimator (10, 10a, 10 b) into a Focal Line (FL) in the focal line region (4),

and wherein the light rays (S3) reflected by the mirror (2) are deflected by the exit lens (3) at least in the vertical direction (V) in such a way that the light rays (S4) emerging from the exit lens (3) form a light distribution having a light-dark boundary, wherein the light-dark boundary is produced by the exit lens (3) as an image of the Focal Line (FL) or the focal line region (4),

and wherein the one or more of the one or more,

the mirror (2), the exit lens (3) and the focal line region (4) and the at least one collimator (10, 10a, 10 b) are formed by a translucent body (101), and wherein at the mirror interface of the mirror (2) and/or the interface of the focal line region (4) and at the collimator interface of the at least one collimator (10, 10a, 10 b) light rays (S1, S2, S3) propagating in the translucent body (101) are completely reflected,

it is characterized in that the preparation method is characterized in that,

the outer surface (3 a) of the exit lens (3) is formed by a groove-shaped structure in a smooth base surface (BF), wherein the grooves (3 b) forming the groove-shaped structure run in the vertical direction, and wherein in each case two grooves (3 b) arranged next to one another in the horizontal direction are separated by a vertically running projection which extends over the entire vertical extension of the groove (3 b), wherein the base surface is of an imaginary configuration with respect to which the outer surface is depicted, wherein,

a second base cutting curve (BSK 2) which is obtained when the base surface is cut with a vertical second cutting plane (SE 2) which runs parallel to the optical axis (Z) of the exit lens (3) is configured to curve outward, wherein the second base cutting curve (BSK 2) is continuous,

a first outer surface cutting curve (SK 1) obtained when cutting the outer surface (3 a) with a first cutting plane (SE 1) connects points of the outer surface (3 a) to each other at a maximum distance from a base surface (BF), wherein the first cutting plane (SE 1) is perpendicular to a tangential plane (TE) of the base surface (BF), wherein,

the standard spacing of the base surface (BF) from the first outer surface cutting curve (SK 1) as a function of a parameter s, which specifies the position on the second base cutting curve (BSK 2), as a function of the second base cutting curve (BSK 2) in the first cutting plane (SE 1), wherein,

the standard distance a(s) increases continuously as one progresses along the second basic cutting curve (BSK 2), wherein the standard distance at the lower edge of the basic surface (BF) is smaller than the standard distance at the upper edge of the basic surface, wherein lower and upper are understood as the orientation of the lighting unit when installed in a lighting device installed in a vehicle, wherein the standard distance a(s) follows the relation a(s) = a₀(K-s) wherein s [0,1 ]]Wherein s =0 represents the upper edge and s =1 represents the lower edge, and K =1 or K>1, wherein A₀Is a standard spacing at the upper or lower edge of the base surface (BF);

the first base cutting curve (BSK 1) obtained when cutting the base surface (BF) with the non-vertical first cutting plane (SE 1) extends straight, and the first outer surface cutting curve (SK 1) obtained when cutting the outer surface (3 a) with the first cutting plane (SE 1) has a sinusoidal course, wherein the amplitude of the sine is determined from a certain starting value A at the upper edge of the light exit surface₀To a value of zero at the lower edge of the lens.

2. The lighting unit of claim 1, wherein the first outer surface cut curve is a first base cut curve (BSK 1) and sin in a first cut plane (SE 1) with respect to a respective first cut plane (SE 1)^N(k x) proportionally extends, wherein N =1, 2, 3The coordinates of a base cutting curve and k represents a constant.

3. The lighting unit according to claim 2, characterized in that the zero crossings of the sinusoidal first outer surface cut curve are on a first base cut curve (BSK 1).

4. A lighting unit as claimed in claim 2 or 3, characterized in that the value for the constant k is the same for all first outer surface cut curves.

5. A lighting unit as claimed in any one of claims 1 to 3, characterized in that the at least one light source is arranged deeper than the focal line region (4) and light emitted by the at least one light source is directed upwards for reflection by the reflector (2) downwards in the direction of the focal line region (4).

6. A lighting unit as claimed in any one of claims 1 to 3, characterized in that the at least one light source is arranged higher than the focal line region (4) and that the light emitted by the at least one light source is conducted downwards for being able to be reflected by the reflector (2) upwards in the direction of the focal line region (4).

7. A lighting unit as claimed in any one of claims 1 to 3, characterized in that the reflector (2) is a surface having a parabola as a conductor.

8. A lighting unit as claimed in any one of claims 1 to 3, characterized in that the outer surface (3 a) of the exit lens (3) is curved outwards in a vertical direction.

9. A lighting unit as claimed in claim 7, characterized in that the cylindrical surface of the outer surface (3 a) has busbars which are parallel to busbars of the reflector.

10. A lighting unit as claimed in any one of claims 1 to 3, characterized in that a plurality of light sources (1, 1a, 1 b) are arranged side by side.

11. A lighting unit as claimed in any one of claims 1 to 3, characterized in that the at least one light source (1, 1a, 1 b) comprises a light emitting diode or a plurality of light emitting diodes.

12. A lighting unit as claimed in claim 7, characterized in that the reflector (2) is a cylindrical surface.

13. The lighting unit of claim 7, wherein the focal line of the reflector is formed by a straight line.

14. The lighting unit of claim 13, wherein the straight line is parallel to a generatrix of the post.

15. A lighting unit as claimed in claim 8, characterized in that the outer surface (3 a) of the exit lens (3) extends straight in the horizontal direction.

16. A lighting unit as claimed in claim 8, characterized in that the outer surface (3 a) of the exit lens (3) is formed by a cylindrical surface with a straight cross section along an outwardly convex curve.

17. Lighting unit according to claim 10, characterized in that a plurality of light sources (1, 1a, 1 b) are arranged side by side in the direction of a generatrix of the reflector (2).

18. Motor vehicle headlight with at least one lighting unit according to any of the claims 1 to 17.